Preparation And Characerization Of Antimicrobial Regenerated Cellulose Fiber

Regenerated cellulose fiber is becoming more and more important in the field of garments due to its characteristics of excellent moisture absorption,air permeability and comfort as well as the people's rising awareness of “Green Life” concept.However,cellulose fiber is more susceptible to microorganism attacks than synthetic products like nylon,polyester and polyurethane because of its large surface area and hydrophilic structure,which can provide a moist and warm environment for microorganism growth,so it is urgent for us to develop antimicrobial cellulose fiber.In this paper,novel non-water polymeric guanidine derivatives were synthesized and co-dissolved with cellulose in [BMIM]Cl for obtaining homogeneous solution.Then the antimicrobial regenerated cellulose fiber was prepared by dry-jet-wet spinning technology.The effects of antimicrobial agent content and spinning technics on the structure and properties of regenerated cellulose fibers were studied.Three kinds of novel non-water soluble polymeric guanidine derivatives,polyhexamethylene guanidine dodecyl benzene sulfonate(PHGDBS),polyhexamethylene guanidine dodecyl sulfate(PHGDSA)and polyhexamethylene guanidine laurylsulfonate(PHGLSO)were synthesized based on the precipitation reaction of polyhexamethylene guanidine hydrochloride with three anionic surfactants,sodium dodecyl benzene sulfonate,sodium dodecyl sulfate and sodium dodecyl sulfate,respectively.The chemical composition and structure were characterized by elemental analysis,Flourier transformation infrared spectroscopy(FTIR)and Hydrogen nuclear magnetic resonance spectroscopy(1H-NMR).Their solubility in different solvents were also determined.Differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA)were used to evaluate their thermal heating properties and thermal stability.Moreover,their antimicrobial properties were determined by the inhibition zone method.The results showed that three polymeric guanidine derivatives were coincident with the expected structure.They were soluble in ionic liquid 1-butyl-3-methylimidazolium chloride([BMIM]Cl)and 4-Methylmorpholine N-oxide monohydrate(NMMO·H2O),which are two typical novel solvents for cellulose.They also have excellent thermal stability so they can be applied for further application which are exposed to high temperature.Moreover,they have excellent antimicrobial properties against both bacterial and fungi,and [BMIM]Cl had no negative effect on their antimicrobial properties.Based on the above research results,cellulose/PHGDBS/[BMIM]Cl solutions with varied PHGDBS content were prepared,and the influence of PHGDBS on the cellulose /[BMIM]Cl solution was studied by steady shear experiments,dynamic rheology measurement and temperature scan test.It was found that when temperature at 90 °C,the viscosity of the cellulose solution increased with the increase of PHGDBS,while PHGDBS haven't produced more microphase separation structure in solution.When at low temperature(30-10 °C),the cellulose /PHGDBS/[BMIM]Cl solution had higher gel-sol phase transition temperature,indicating that PHGDBS can produce more microphase separation structure.In addition,the cellulose/PHGDBS/[BMIM]Cl solutions with different PHGDBS content were prepared and dry-jet-wet spinning technology was used for obtaining antimicrobial regenerated cellulose fiber.Tensile strength test,Wide Angle X-ray Scatterign(SAXS),Laser Scannning Confocal Microscope(LSCM)and shaking flask method were used to study the effects of PHGDBS content,coagualtion bath temperature and spinning speed on the structure and properties of cellulose fiber.The results showed that the regenerated cellulose fiber contained only 2%PHGDBS showed excellent antibacterial properties and laudering durability,still over 90% bacteria reduction remained after 15 laundering times.The loss of PHGDBS mainly occurred in the coagulation bath.When coagulation bath temperature rose,the diameter of fiber became larger and unstable,the crystal orientation and crystallinity decreased,which result in the decrease of the breaking strength of cellulose fiber.PHGDBS tended to be distributed on the surface of cellulose fiber with the increase of cogualation temperature.When spinning speed increased,the crystal orientation and crystallinity slightly increased,resulting in the increase of breaking strength.Meanwhile,PHGDBS tended to be distributed in the surface of cellulose fiber when spinning speed increased.Antimicrobial cellulose fibers obtained from higher spinning speed have better washing fastness.Above all,it can be concluded that antimicrobial cellulose fiber with both high strength and excellent lasting antibacterial ability can be obtained from low coagulation bath temperature and high spinning speed.